Ethyl-cellulose

Solvents recommended are ethylene dichloride, butyl alcohol, and ethyl acetate. Mixtures suggested are  

For a bodied cement, a suggested formulation is to use solvent solutions of the polymer ethyl cellulose in ethyl acetate/ethyl cellulose (80/20). 

By use of a modification of the well-known Williamson synthesis it is possible to prepare a number of cellulose ethers. Of these materials ethyl cellulose has found a small limited application as a moulding material and somewhat greater use for surface coatings. The now obsolete benzyl cellulose was used prior to World War II as a moulding material whilst methyl cellulose, hyroxyethyl cellulose and sodium carboxymethyl cellulose are useful water-soluble polymers. 

With each of these materials the first step is the manufacture of alkali cellulose (soda cellulose). This is made by treating cellulose (either bleached wood pulp or cotton linters) with concentrated aqueous sodium hydroxide in a nickel vessel at elevated temperamre. After reaction excess alkali is pressed out, and the resultant cake is then broken up and vacuum dried until the moismre content is in the range 10-25%. The moisture and combined alkali contents must be carefully controlled as variations in them will lead to variations in the properties of the resultant ethers. 

Ethyl cellulose is prepared by agitating the alkali cellulose with ethyl chloride in the presence of alkali at about 60°C for several hours. Towards the end of the reaction the temperature is raised to about 130-140°C. The total reaction time is approximately 12 hours. The reaction is carried out under pressure. 

It is essential that there be sufficient alkali present, either combined with the cellulose, or free, to neutralise the acid formed by both the main reaction and in a side reaction which involves the hydrolysis of ethyl chloride. 

Ethyl ether and ethyl alcohol which are formed as by-products are removed by distillation and the ethyl cellulose is precipitated by hot water. The polymer is then carefully washed to remove sodium hydroxide and sodium chloride and dried. 

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McjC = CHCOCH3. Colourless liquid b.p. 129"C, with a strong peppermint-like odour. Prepared by distilling diacetone alcohol in the presence of a trace of iodine. Converted to phorone by heating in propanone with dehydrating agents such as sulphuric acid. It is a solvent For cellulose acetate and ethyl-cellulose and other polymers. 

Ethyl Cellulose. Ethyl cellulose is prepared by reacting cellulose with caustic to form caustic cellulose, which is then reacted with chloroethane to form ethyl cellulose. Plastic-grade material contains 44 to 48% ethoxyl. 

PVF resins are generally compatible with phthalate, phosphate, adipate, and diben2oate plastici2ers, and with phenoHc, melamine—formaldehyde, urea—formaldehyde, unsaturated polyester, epoxy, polyurethane, and cellulose acetate butylate resins. They are incompatible with polyamide, ethyl cellulose, and poly(vinyl chloride) resins (141). 

Properties. Ethyl cellulose [9004-57-3] (EC) is a nonionic, organo-soluble, thermoplastic cellulose ether, having an ethyl DS in the range of 2.2-2.7. Actually, EC is water-soluble at DS 1.2, but only those products that are thermoplastic and soluble in organic solvents are of commercial importance, because of thek abiUty to form tough, stable films. Above a DS of about 2.5, EC is soluble in many nonpolar solvents. 

Cellulose nitrate Cellulose acetate Cellulose accetate- hutyrate Cellulose acetate- propionate Cellulose propionate Ethyl cellulose... 

Figure 22.6. Influence of the ethoxyl content of ethyl cellulose on softening point moisture absorption and hardness. (Hercules Powder Co. literature)...

Typical physical properties of ethyl cellulose are compared with those of the cellulose ethers in Table 22.2. 

The ether is also used in paint, varnish and lacquer formulations. A recent development is the use of ethyl cellulose gel lacquers. These are permanent coatings applied in a similar way to the strippable coatings. They have been used in the United States for coating tool handles, door knobs and bowling pins. 

A number of water-soluble cellulose ethers are marketed." Methyl cellulose is prepared by a method similar to that used for ethyl cellulose. A degree of substitution of 1.6-1.8 is usual since the resultant ether is soluble in cold water but not in hot. It is used as a thickening agent and emulsifier in cosmetics, as a paper size, in pharmaceuticals, in ceramics and in leather tanning operations. 

Group of plastics composed of cellulose compounds, for example esters (e.g., cellulose acetate) and ethers (e.g., ethyl cellulose). 

Acrvlonttrlle-Methylmethacrylote Cellulose Acetate Cellulose Acetat Butyrate Cellulose Acetote roplonote Cellulose NHrate Cellulose Proprlonote Cellulose Triacetate Diollyl Phthalote Ethyl Cellulose Epoxy... 

Our results [104,117] have shown that the extended chains of ethyl cellulose liquid crystal at high pressures can act as the nucleus of PE ECC and induce the formation of ECC. (The details will be introduced in Section IX.)... 

Figure 13 Schematic diagram of the dependence of <7 on pressure. (F) Denotes folded-chain nucleus, (B) denotes bundle-like nucleus and (B ) denotes addition of ethyl cellulose liquid crystal polymer. (From Refs. 104, 110, 111, and 117.)...

Figure 21 DSC melting curves at atmospheric pressure for PE-ethyl cellulose mixture crystallized at elevated pressure. (a) 100 MPa (b) 150 MPa (c) 300 MPa (d) 400 MPa and (e) 750 MPa. (From Ref. 117.)...

A result different from that of Nakafuku et al. [144-147] was obtained by us from the study of a binary mixture of PE-ethyl cellulose liquid crystal under high pressure. We have reported [104,117] that addition of 1% ethyl cellulose by weight facilitates the formation of ECC of PE and moderates the conditions for the formation of ECC, that is, the pressure limit is lowered from 440 MPa to 150-200 MPa, and the temperature limit lowered from 200-245°C to 170°C. The DSC melting curves at atmospheric pressure for pure PE (Mt, = 1.06 x 10, p = 0.9556 g/cm ) and PE-ethyl cellulose mixture crystallized at various pressures are shown in Figs. 20 and... 

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